FTFreeTools
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WCAG Contrast Checker

Enter a foreground and a background colour, get the WCAG contrast ratio and whether AA / AAA pass, with colour-blindness previews.

Runs in browserAccessibilityContrast

Last changed in v0.9.4

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How to use

  1. Enter a foreground and a background colour (#hex, rgb(), hsl(), oklch() and named colours all work).
  2. The ratio follows the WCAG 2.x formula: relative luminance of the two colours, independent of their order.
  3. All four colour-blindness simulations are shown, each with its own pass or fail verdict.

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